| From e638642b08c170d2021b706f0b1c4f4ae93d8cbd Mon Sep 17 00:00:00 2001 |
| From: "Ahmed S. Darwish" <ahmed.darwish@valeo.com> |
| Date: Mon, 26 Jan 2015 07:25:43 +0200 |
| Subject: can: kvaser_usb: Fix state handling upon BUS_ERROR events |
| |
| From: "Ahmed S. Darwish" <ahmed.darwish@valeo.com> |
| |
| commit e638642b08c170d2021b706f0b1c4f4ae93d8cbd upstream. |
| |
| While being in an ERROR_WARNING state, and receiving further |
| bus error events with error counters still in the ERROR_WARNING |
| range of 97-127 inclusive, the state handling code erroneously |
| reverts back to ERROR_ACTIVE. |
| |
| Per the CAN standard, only revert to ERROR_ACTIVE when the |
| error counters are less than 96. |
| |
| Moreover, in certain Kvaser models, the BUS_ERROR flag is |
| always set along with undefined bits in the M16C status |
| register. Thus use bitwise operators instead of full equality |
| for checking that register against bus errors. |
| |
| Signed-off-by: Ahmed S. Darwish <ahmed.darwish@valeo.com> |
| Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/net/can/usb/kvaser_usb.c | 7 +++---- |
| 1 file changed, 3 insertions(+), 4 deletions(-) |
| |
| --- a/drivers/net/can/usb/kvaser_usb.c |
| +++ b/drivers/net/can/usb/kvaser_usb.c |
| @@ -698,9 +698,7 @@ static void kvaser_usb_rx_error(const st |
| } |
| |
| new_state = CAN_STATE_ERROR_PASSIVE; |
| - } |
| - |
| - if (status == M16C_STATE_BUS_ERROR) { |
| + } else if (status & M16C_STATE_BUS_ERROR) { |
| if ((priv->can.state < CAN_STATE_ERROR_WARNING) && |
| ((txerr >= 96) || (rxerr >= 96))) { |
| cf->can_id |= CAN_ERR_CRTL; |
| @@ -710,7 +708,8 @@ static void kvaser_usb_rx_error(const st |
| |
| priv->can.can_stats.error_warning++; |
| new_state = CAN_STATE_ERROR_WARNING; |
| - } else if (priv->can.state > CAN_STATE_ERROR_ACTIVE) { |
| + } else if ((priv->can.state > CAN_STATE_ERROR_ACTIVE) && |
| + ((txerr < 96) && (rxerr < 96))) { |
| cf->can_id |= CAN_ERR_PROT; |
| cf->data[2] = CAN_ERR_PROT_ACTIVE; |
| |
